1. Field of the Invention
The present invention relates to a parking and power charging system placed in a car park having a plurality of parking spaces with charging devices capable of charging batteries mounted on electric vehicles parked in the parking spaces.
2. Description of the Related Art
There is a car park with a plurality of parking spaces, each of the parking spaces is equipped with a charging device to charge the battery mounted on the parked electric vehicle. The charging devices are electrically connected to a grid power (such as a commercial power) or an off-grid power. Electric vehicles and hybrid vehicles equipped with a drive motor and an on-vehicle battery parked in the parking spaces in the car park are electrically charged by the charging devices.
In general, the electric vehicles and hybrid vehicles to be parked in the parking spaces in the car park are grouped to a company car group, a rent car group, and a resident car group, for example. The vehicles in the company car group are used only by company workers. The vehicles in the rent car group are commercially lent. The vehicles in the resident car group are used by apartment residents.
For example, Japanese patent document No. JP 3901100 discloses an automatic power charging system for charging batteries mounted on electric vehicles and/or hybrid vehicles which are parked in the parking spaces of a car park. The automatic power charging system has a control means and a plurality of charging devices. The control means in the automatic power charging system detects a residual power (or the state of charge: SOC) of the on-vehicle battery mounted on the electric vehicle, and selects, from a plurality of charging levels having a different power level and charging time, an optimum charging level of the electric vehicle on the basis of the detected residual power of the on-vehicle battery mounted on the electric vehicle. The control means in the automatic power charging system then controls the charging device in order to charge the on-vehicle battery of the electric vehicle to the optimum charging level. By the way, the automatic power charging system having the control means described above is designed so that the total sum of the charging power of the charging devices to charge the batteries of the parked electric vehicles which are currently charged not exceed the maximum power capacity of the electric power device in the automatic power charging system.
This configuration of the automatic power charging system makes it possible for the control means to easily control each of the charging devices and to perform the charging operation with high efficiency.
However, in the automatic power charging system disclosed in the Japanese patent document No. JP3901100, the control means selects the charging level of each of the charging devices according to the state of charge (SOC) of the on-vehicle battery, and changes the charging level of the charging device. Further, such a conventional automatic power charging system of a car park supposes that the electric vehicles are always parked at the corresponding same parking spaces. Accordingly, this structure of the conventional automatic power charging system requires each of the charging devices to haves charging performance (such as charging current) capable of charging the maximum charging capacity. Still further, it is difficult or not designed for the conventional automatic power charging system to use charging devices of a different charging performance, and not designed to decrease the capacity of each of the charging devices.